Introduction to instruments
Power measurement at radio frequency
Download 3.23 Mb.
|
Power measurement at radio frequency:The method of using a dummy load and a voltmeter can be used at radio frequencies upto 500 MHz also. In such a case, the voltmeter and load resistor are usually combined into a sirtgle absorption type power meter as shown in the Fig. 
The resistance Rs is so designed that its value remains constant over the entire range of frequencies of interest. The voltmeter is a high "requency meter which is capable of responding to high frequency signals with high accuracy. The power is calculated by using the basic relationship as, 
In practice the standard resistors are available which have constant value for frequencies ranging from d.c. to 4 GHz. This type of power meter is used to measure power below 500 MHz only. To measure power at high frequencies from 500 MHz to 40 GHz two special type of absorption meters are popularly used. These meters are, Calorimeter power meter Bolometer power meter Both these meters use the sensing of heating effects caused by the power signal to be measured. Directory: wp-content -> uploads -> 2017 2017 -> Leadership ohio 2017 -> Ascension Lutheran Church Counter’s Schedule January to December 2017 2017 -> Board of directors juanita Gibbons-Delaney, mha, rn president 390 Stone Castle Pass Atlanta, ga 30331 2017 -> Military History Anniversaries 16 thru 31 January Events in History over the next 15 day period that had U. S. military involvement or impacted in some way on U. S military operations or American interests 2017 -> The Or Shalom Cemetery Community Teaching on related issues of Integral 2017 -> Ford onthult samenwerking met Amazon Alexa en introduceert nieuwe navigatiemogelijkheden van Ford sync® 3 met Applink 2017 -> Start Learn and Increase gk. Question (1) Name the term used for talking on internet with the help of text messege? 2017 -> Press release from 24. 03. 2017 From a Charleston Car to a Mafia Sedan 2017 -> Tage Participants 2017 -> Citi Chicago Debate Championship Varsity and jv previews Download 3.23 Mb. Share with your friends:
|